Hamann had already informed manager Sam Allardyce of his decision to turn Bolton down — but no one had bothered to tell Liverpool.

Bolton, who did not register Hamann with the Premier League, issued a statement which read: "Bolton Wanderers wish to clarify that although Didi Hamann signed a contract with the club, he has since had a change of heart and will join another football club in the next 24 hours."

'I don't know why he's changed his mind, I haven't had an explanation'

Allardyce has tracked Hamann for two years and is deeply disappointed at the U-turn. He was also given assurances last summer that the former Germany international would move to the Reebok, only for the player to decide to stay at Anfield.

Having first considered returning to Germany, Hamann is understood to have signed a pre-contract document with Bolton before telling Allardyce that he had had second thoughts, leaving the manager frustrated but unable to enforce the arrival of a reluctant recruit.

Allardyce admitted: "As manager of Bolton you get far more disappointments than successes. I would have liked Hamann but we haven't got him. I don't know why he's changed his mind, I haven't had an explanation. It's a big disappointment, but we haven't got him, so we move on."

While Hamann's brief pit-stop is unorthodox, a Premier League spokesman confirmed: "If he hasn't been registered for Bolton, there is not an issue."

Hamann, who cost Liverpool £8million from Newcastle United, will now become City boss Stuart Pearce's fourth signing of the summer.